Laser processing of a moving web with one or more laser beams can be done to increase speed and efficiency of a laser system. Existing laser perforation systems commonly employ some sort of scanning system or galvanometer (or “galvo” for short) system for directing a laser beam. The galvanometer may utilize rotatable mirrors to move a laser beam or beams across the web in a predetermined pattern. Alternatively, in a perforating system it is also common to use a fixed beam that is pulsed on and off to create perforations in the web direction. The system that this technology has been implemented on is designed to be flexible and form perforations, slits, profiled cutouts, laser scoring, and singulated parts.
The laser beams generate heat and at least some of this heat generated is absorbed by the galvo system or galvo systems for direction and steering the beams along the substrate and/or web. The galvo systems are further susceptible to damage from heat as each mirror in the galvo system is independently steered by a respective motor, which also generates heat during operation. A mechanism may be incorporated into laser systems to reduce the heat effects on the galvo systems as the mirrors can be damaged, especially with higher powered lasers. Accuracy of the laser steering may also be negatively impacted. If a mirror starts to overheat, it can damage the reflective coating thus absorbing more laser light and heat and making it inoperable. Thus, a method of creating air flow such as using compressed air or cooling fans may be installed to cool down the galvo systems.
When laser processing a substrate, debris may also accumulate in the system and if not controlled, may negatively impact the galvo systems. Protection windows are incorporated to prevent debris from entering the galvo systems, however these windows generally require cleaning of accumulated debris to ensure laser beam accuracy.